To reduce greenhouse gas emissions, biomass fuels are used to gradually replace fossil fuels in the sintering process. Unfortunately, the sinter quality will deteriorate sharply due to too fast combustion rate when using biomass fuels. To address this problem, pregranulation proved to be an effective method. In this study, the pilot-scale sinter pot tests were carried out to study the effect of coating structure of granulated quasi-fuel particles on the granulation properties, flame front propagation in sintering, sinter indexes, sinter mineralogy, and pore structure. The experimental results show that when substituting coke with biomass char, the average size of the granules decreased whereas bed voidage increased due to the irregular shape and lower apparent density of granules. Pregranulation can reduce the flame front speed and increase the maximum bed temperature, thereby alleviating the deterioration of sinter quality and sinter yield. By pregranulating biomass char and 2% magnetite concentrate, the tumbler strength, sinter yield, and productivity can be increased from 44.9% to 55.0%, from 41.9% to 49.3%, and from 28.54 to 31.10 t/m²/d, respectively. The microscopic observation results show that substituting coke with biomass char for sintering decreased the content of calcium ferrite in sinter and increased sinter porosity. On the contrary, pregranulating increased calcium ferrite content in sinter and decreased sinter porosity, and thus sinter quality was improved.

中文翻译：

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粒状准燃料颗粒包覆结构对铁矿石烧结的影响

为减少温室气体排放，生物质燃料在烧结过程中逐渐替代化石燃料。不幸的是，当使用生物质燃料时，由于燃烧速度太快，烧结质量会急剧恶化。为了解决这个问题，预制粒被证明是一种有效的方法。在这项研究中，进行了中试规模的烧结罐试验，以研究粒状准燃料颗粒的涂层结构对造粒性能、烧结中的火焰前沿传播、烧结指标、烧结矿物学和孔隙结构的影响。实验结果表明，当用生物质炭代替焦炭时，由于颗粒的不规则形状和较低的表观密度，颗粒的平均尺寸减小，而床空隙率增加。预制粒可以降低火焰前沿速度，提高床层最高温度，从而缓解烧结质量和烧结产率的恶化。通过对生物质炭和 2% 的磁铁矿精矿进行预制粒，转鼓强度、烧结产量和生产率可以从 44.9% 提高到 55.0%，从 41.9% 提高到 49.3%，从 28.54 到 31.10 t/m² / d，分别。显微观察结果表明，用生物质炭代替烧结焦，降低了烧结矿中铁酸钙的含量，增加了烧结矿的孔隙率。相反，预制粒增加了烧结矿中铁酸钙含量，降低了烧结矿孔隙率，从而提高了烧结矿质量。